Unable to connect to the data source undefined.

ivannye , refer if these can help you to solve the issue- Key did not match

https://blog.crossjoin.co.uk/2020/04/06/understanding-the-the-key-didnt-match-any-rows-in-the-table-error-in-power-query-in-power-bi-or-excel/

https://community.powerbi.com/t5/Desktop/Expression-Error-The-key-didn-t-match-any-rows-in-the-table/td-p/155986

https://community.powerbi.com/t5/Power-Query/Expression-Error-The-key-did-not-match-any-rows-in-the-table/td-p/9824/page/2

Have you got any security filters applied? This error usually means the table/query is empty. Might also be an issue with authentication. 

Hi, ivannye 

According to your description, You said that it can be refreshed normally in the desktop, but after publishing to service, you can't connect to the gateway and refresh, right?

If so, You need to check whether the name of the database or instance name is correct,and authentication and elsewhere may appear mismatched. The problem is usually the failure to identify the correct table. Need to investigate one by one.

If it doesn’t solve your problem, please feel free to ask me.

Best Regards

Janey Guo

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Hi, ivannye 

Have your problem been solved? If you take the answer of someone, please mark it as the solution to help the other members who have same problems find it more quickly. If not, let me know and I'll try to help you further. Thanks.

Best Regards

Janey Guo